#include <iostream>
using std::ostream;
using std::cout;
using std::endl;
#include <string>

class HasPtr
{
public:
	// no point to passing a pointer if we're going to copy it anyway
	// store pointer to a copy of the object we're given
	HasPtr(const int& p, int i): ptr(new int(p)), val(i) {}

	// copy members and increment the use count
	HasPtr(const HasPtr& orig):
		ptr(new int (*orig.ptr)), val(orig.val) { }

	HasPtr& operator=(const HasPtr&);
	// wrong: don't define a destructor without also defining copy and assign
	~HasPtr()
	{
		delete ptr;
	}
	friend ostream& operator<<(ostream&, const HasPtr&);

	// accessors must change to fetch value from Ptr object
	int get_ptr_val() const
	{
		return *ptr;
	}
	int get_int() const
	{
		return val;
	}

	// change the appropriate data member
	void set_ptr(int* p)
	{
		ptr = p;
	}
	void set_int(int i)
	{
		val = i;
	}

	// return or change the value pointed to, so ok for const objects
	int* get_ptr() const
	{
		return ptr;
	}
	void set_ptr_val(int p) const
	{
		*ptr = p;
	}
private:
	int* ptr;        // points to an int
	int val;
};

HasPtr& HasPtr::operator=(const HasPtr& rhs)
{
	// Note: Every HasPtr is guaranteed to point at an actual int;
	//       We know that ptr cannot be a zero pointer
	*ptr = *rhs.ptr;      // copy the value pointed to
	val = rhs.val;        // copy the int
	return *this;
}

ostream& operator<<(ostream& os, const HasPtr& hp)
{
	os << "*ptr: " << hp.get_ptr_val() << "\tval: " << hp.get_int() << endl;
	return os;
}

int main()
{
	int obj = 0;

	HasPtr ptr1(obj, 42);  // int* member points copy of obj, val is 42
	HasPtr ptr2(ptr1);     // int* member points new copy obj, val is 42

	cout << "(1) ptr1: " << ptr1 << endl << "ptr2: " << ptr2 << endl;

	ptr1.set_ptr_val(42); // sets copy in ptr1; value in ptr2 unchanged
	ptr2.get_ptr_val();   // returns 0

	cout << "(2) ptr1: " << ptr1 << endl << "ptr2: " << ptr2 << endl;

	ptr1.set_int(0);   // changes val member only in ptr1
	ptr2.get_int();    // returns 42
	ptr1.get_int();    // returns 0

	cout << "(3) ptr1: " << ptr1 << endl << "ptr2: " << ptr2 << endl;

	int* ip = new int(42); // dynamically allocated int initialized to 42
	HasPtr ptr(*ip, 10);    // HasPtr points to same object as ip does
	delete ip;          // object pointed to by ip is freed
	ptr.set_ptr_val(0); // ok: ptr has its own copy

	cout << "(4) ptr: " << ptr << endl;
}
